From: | Heikki Linnakangas <hlinnakangas(at)vmware(dot)com> |
---|---|
To: | Sergey Konoplev <gray(dot)ru(at)gmail(dot)com>, Ivan Voras <ivoras(at)freebsd(dot)org> |
Cc: | Jeff Janes <jeff(dot)janes(at)gmail(dot)com>, postgres performance list <pgsql-performance(at)postgresql(dot)org> |
Subject: | Re: tsearch2, large data and indexes |
Date: | 2014-04-25 06:37:52 |
Message-ID: | 535A02C0.8060504@vmware.com |
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Lists: | pgsql-performance |
On 04/24/2014 10:57 PM, Sergey Konoplev wrote:
> On Thu, Apr 24, 2014 at 5:34 AM, Ivan Voras <ivoras(at)freebsd(dot)org> wrote:
>> On 24 April 2014 13:34, Heikki Linnakangas <hlinnakangas(at)vmware(dot)com> wrote:
>>
>>> As the docs say, the GIN index does not store the weights. As such, there is
>>> no need to strip them. A recheck would be necessary if your query needs the
>>> weights, precisely because the weights are not included in the index.
>>>
>>> (In the OP's query, it's the ranking that was causing the detoasting.)
>>
>> Thanks!
>>
>> My problem is that I actually need the ranking. My queries can return
>> a large number of documents (tens of thousands) but I usually need
>> only the first couple of pages of most relevant results (e.g. 50-100
>> records). With PostgreSQL and tsearch2, this means that the tens of
>> thousands of documents found via the index are then detoasted and
>> ranked.
>
> Heikki, what about the "GIN improvements part 3: ordering in index"
> patch, was it committed?
>
> http://www.postgresql.org/message-id/flat/CAPpHfduWvqv5b0XZ1DZuqAW29erDCULZp2wotfJzDBs7BHpKXw(at)mail(dot)gmail(dot)com
Nope, wasn't committed.
- Heikki
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